Wet sanding with an electric sander

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Wet sanding with an electric sander

Postby Brian Evans » Mon Jul 09, 2018 1:30 pm

Just to close off this question for myself, anyway, I was having issues with scratches that would not clear after polishing, with hand-sanding with 1200 grit and mineral oil. I put a sheet of 1200 in my quarter-sheet Porter Cable sander, lubed well with the mineral oil and lightly wet sanded. did not make a mess, I was careful to keep it wet, and polishing out went very well, no scratches that I can see with 2X magnification, so I call it a success.

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Re: Wet sanding with an electric sander

Postby Steve Sawyer » Mon Jul 09, 2018 2:11 pm

That's interesting, Brian.

My son went out and bought some fine (2000-4000 grit) 3" hook-and-loop sanding disks, and borrowed my 3" Griot polisher to do some finish sanding on his car. He got very good results. I'm really tempted to do some experimenting with that. I'm going to do some testing with Brite Tone on some scrap and may give this a try. The foam padding on the backs of these disks is a bit "squishy", so obviously not good for level-sanding, but might be suitable for the finish sanding.
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Re: Wet sanding with an electric sander

Postby Brian Evans » Mon Jul 09, 2018 4:24 pm

I've been using 600 grit open coat Fre-Cut 3M paper on the palm sander to level sand after spraying as a first step. It works really well, the pad on the 1/4 sheet sander is only 1/8" thick so creates level quite well. The sandpaper clears really easily by wiping on a towel, and lasts seemingly forever. I feel like I'm kind of getting a rhythm down for finishing now...
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Re: Wet sanding with an electric sander

Postby Andy Bounsall » Mon Jul 09, 2018 4:36 pm

I’ve always been a bit leery of leveling with a powered sander, fearing that it might be too aggressive. I assume you’re talking about a random orbital sander, correct?
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Re: Wet sanding with an electric sander

Postby Steve Sawyer » Mon Jul 09, 2018 10:32 pm

I don't know about Brian's palm sander, but the Griot's polisher I'm going to try is indeed a random-orbit tool.
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Re: Wet sanding with an electric sander

Postby Brian Evans » Tue Jul 10, 2018 10:28 am

This: https://www.portercable.com/products/po ... sander/380

It's much less aggressive than a typical random orbital sander, which I use for shaping and rough finishing, and polishing with thick foam pads. It is the one recommended by Bob Benedetto for finish sanding. I find hand sanding to be too scratch-inducing compared to the 1/4 sheet sander, which uses tiny circles and leaves almost no long scratches that catch the eye. I'm really quite pleased I tried it. I found it extremely controllable in the recurve area, up to the edges, and cleaning up and blending a few runs. Although why I can spray 10 coats without runs and get runs on the 11th and final coat I have not yet figured out.
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Re: Wet sanding with an electric sander

Postby Steve Sawyer » Tue Jul 10, 2018 11:32 am

Brian Evans wrote:Although why I can spray 10 coats without runs and get runs on the 11th and final coat I have not yet figured out.


The perversity of the universe tends toward a maximum. :lol:

Also, interesting that your P-C sander is orbital, but not random orbital. Maybe the regularity of the scratch pattern is a plus?
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